SIMS and Raman characterizations of ZnO:N thin films grown by MOCVD

摘要

Nitrogen was incorporated into ZnO films grown by metalorganic chemical vapour deposition (MOCVD) on ZnO substrates using DMZn-TEN, tert-butanol and diallylamine, respectively, as zinc, oxygen and doping sources. The carrier gas was either hydrogen or nitrogen and the partial pressure ratio (R_(Ⅵ/Ⅱ)) was varied in order to favor the nitrogen incorporation and/or reduce carbon related defects. The ZnO films have been characterized by Micro-Raman scattering and SIMS measurements. SIMS measurements confirm the nitrogen incorporation with concentrations extending from ～10~(19)cm~(-3) to ～4 × 10~(20)cm~(-3). Raman spectra show nitrogen local vibration modes in films grown at low R_(Ⅵ/Ⅱ) ratio and using H_2 as carrier gas. However, a vibration band attributed to carbon clusters dominates the Raman spectra for films grown with N_2 carrier. The contribution of N complexes was discussed. The strain was calculated for the as-grown and annealed films and it changes from tensile to compressive after annealing.